Gastric and duodenal ulcers are diseases of the digestive tract which are induced by various causes such as mental stress, eating habits and intake of stimulative drinks and food. These diseases are caused by the autolysis of the mucous membranes of the digestive tract with gastric juices and are generally referred to as peptic ulcers. Peptic ulcers are caused by the increase of gastric acid, pepsin and like causative factors, and by the inability to prevent the increase of these factors due to the weakening of the body's defense mechanisms.
Examples of pharmaceutical preparations to be used in the treatment of gastric and duodenal ulcers, through the inhibition of the causative factors include an antacid which neutralizes gastric acid, an anti-pepsin agent, a gastric mucosa protecting agent, an anticholinergic drug which inhibits secretion of gastric acid, a parasympatholytic drug, an H.sub.2 blocker, a PPI, and like factors.
The aforementioned H.sub.2 blocker used frequently in recent years as a therapeutic drug for treatment of ulcers inhibits the secretion of hydrochloric acid and pepsin from gastric juice-secreting cells. As a result, autolysis in the stomach is inhibited and a therapeutic effect achieved. The aforementioned PPI inhibits the proton pump ((H.sup.+ +K.sup.+)-ATPase) and thus exerts a wider range of inhibiting action against various stimulants of acid secretion than H.sub.2 blockers.
In order to obtain a greater therapeutic effect, the H.sub.2 blocker and/or the PPI has been combined together or prescribed together with an antacid such as magnesium oxide, aluminum hydroxide, magnesium hydroxide, magnesium tri-silicate, magnesium carbonate or sodium citrate.
In general, ingested food is digested via a complex process. As a general rule, ingested food is first hydrolyzed by .alpha.-amylase secreted from the salivary glands. Next, in the stomach it is digested by pepsin under acidic conditions in the presence of hydrochloric acid. Thereafter, in the intestines it is digested by various enzymes secreted from the pancreas. Finally, the nutritive components are absorbed by the digestive tract wall.
When an Hz blocker or PPI is used for the purpose of treating ulcers, the secretion of hydrochloric acid and pepsin is inhibited so that the digestive functions of the stomach become greatly inhibited. Autolysis of the gastric wall by gastric juices is the main cause of ulcers as described above. Thus, digestion of food in the stomach is greatly inhibited during such treatment of ulcers using an H.sub.2 blocker or PPI.
However, it is necessary to maintain the proper conditions for absorption of nutritive components for the purpose of recovering from diseases of the digestive tract induced by various causes such as mental stress and the like. Thus, it is important to carry out the treatment of diseases of the digestive tract under conditions where the natural mechanism for digestion in the living body can be maintained at its optimum.
According to certain studies conducted by the inventors of the present invention, it was found that digestion of food with gastric juices in the living body promotes subsequent digestion with pancreatic juices and, also, enhances absorption of nutritive components by the digestive tract. Thus, such results confirm that the process involved in the digestion of food in the stomach is a markedly important process of the digestive system of the living body. Consequently, much concern has been directed toward the development of a method by which the normal gastric digestion of food can be maintained and the inhibition of digestive functions by an H.sub.2 blocker or PPI can be prevented without diminishing the therapeutic effect of the H.sub.2 blocker or PPI in treating ulcers.